中国物理B ›› 2019, Vol. 28 ›› Issue (7): 77105-077105.doi: 10.1088/1674-1056/28/7/077105

所属专题: SPECIAL TOPIC — Topological semimetals

• SPECIAL TOPIC—Recent advances in thermoelectric materials and devices • 上一篇    下一篇

Structural, elastic, and electronic properties of topological semimetal WC-type MX family by first-principles calculation

Sami Ullah, Lei Wang(王磊), Jiangxu Li(李江旭), Ronghan Li(李荣汉), Xing-Qiu Chen(陈星秋)   

  1. 1 Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China;
    2 University of Chinese Academy of Sciences, Beijing 100049, China;
    3 School of Materials Science and Engineering, University of Science and Technology of China, Shenyang 110016, China
  • 收稿日期:2019-03-09 修回日期:2019-05-12 出版日期:2019-07-05 发布日期:2019-07-05
  • 通讯作者: Xing-Qiu Chen E-mail:xingqiu.chen@imr.ac.cn
  • 基金资助:

    Project supported by the National Natural Science Foundation of China (Grant No. 51671193). All calculations have been performed on the high-performance computational cluster in the Shenyang National University Science and Technology Park.

Structural, elastic, and electronic properties of topological semimetal WC-type MX family by first-principles calculation

Sami Ullah1,2, Lei Wang(王磊)1,3, Jiangxu Li(李江旭)1,3, Ronghan Li(李荣汉)1,3, Xing-Qiu Chen(陈星秋)1   

  1. 1 Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China;
    2 University of Chinese Academy of Sciences, Beijing 100049, China;
    3 School of Materials Science and Engineering, University of Science and Technology of China, Shenyang 110016, China
  • Received:2019-03-09 Revised:2019-05-12 Online:2019-07-05 Published:2019-07-05
  • Contact: Xing-Qiu Chen E-mail:xingqiu.chen@imr.ac.cn
  • Supported by:

    Project supported by the National Natural Science Foundation of China (Grant No. 51671193). All calculations have been performed on the high-performance computational cluster in the Shenyang National University Science and Technology Park.

摘要:

Recently, the non-centrosymmetric WC-type materials (i.e., MoP, ZrTe, TaN, etc) have attracted extensive interest due to the discovery of their topological properties. By means of the first-principles calculations, here we have investigated the structural, thermodynamic, elastic, and electronic properties of the WC-type MX compounds (TiS, TiSe, TiTe, ZrS, ZrSe, ZrTe, HfS, HfSe, and HfTe). Among these nine compounds, five of them (TiS, ZrS, ZrSe0.9, ZrTe, and Hf0.92Se) have been experimentally synthesized to crystallize in the WC-type structure and other four members have never been reported. Our calculations demonstrated that they are all structurally, thermodynamically, and dynamically stable, indicating that all of them should be possibly synthesized. We have also derived their elastic constants of single crystalline and their bulk and shear moduli in terms of the R. Hill approximations. Furthermore, in similarity to ZrTe, all these compounds have been theoretically derived to be topological semimetals. Whereas TiS is unique because of the coexistence of the Dirac nodal lines (DNLs) and sixfold degenerate nodal points (sixfold DNPs), the other eight members are revealed to exhibit coexisted Weyl nodes (WPs) and triply degenerate nodal points (TDNPs). Their electronic and topological properties have been further discussed.

关键词: topological semimetals, WC-type materials, MX family, elastic properties

Abstract:

Recently, the non-centrosymmetric WC-type materials (i.e., MoP, ZrTe, TaN, etc) have attracted extensive interest due to the discovery of their topological properties. By means of the first-principles calculations, here we have investigated the structural, thermodynamic, elastic, and electronic properties of the WC-type MX compounds (TiS, TiSe, TiTe, ZrS, ZrSe, ZrTe, HfS, HfSe, and HfTe). Among these nine compounds, five of them (TiS, ZrS, ZrSe0.9, ZrTe, and Hf0.92Se) have been experimentally synthesized to crystallize in the WC-type structure and other four members have never been reported. Our calculations demonstrated that they are all structurally, thermodynamically, and dynamically stable, indicating that all of them should be possibly synthesized. We have also derived their elastic constants of single crystalline and their bulk and shear moduli in terms of the R. Hill approximations. Furthermore, in similarity to ZrTe, all these compounds have been theoretically derived to be topological semimetals. Whereas TiS is unique because of the coexistence of the Dirac nodal lines (DNLs) and sixfold degenerate nodal points (sixfold DNPs), the other eight members are revealed to exhibit coexisted Weyl nodes (WPs) and triply degenerate nodal points (TDNPs). Their electronic and topological properties have been further discussed.

Key words: topological semimetals, WC-type materials, MX family, elastic properties

中图分类号:  (Electron density of states and band structure of crystalline solids)

  • 71.20.-b
71.55.Ak (Metals, semimetals, and alloys) 62.20.-x (Mechanical properties of solids)